Coronary angiography is currently the most prevalent use of cardiac CT. Assessment of regional myocardial function has value in the diagnosis and monitoring of myocardial ischemia and myocardial dyssynchrony. Most mechanical analyses in the clinical setting are based on echocardiographic methods derived from two-dimensional motion data. Not all tomographic imaging modalities are capable of producing data with adequate temporal and spatial resolution for detailed regional function assessment. One difficulty with quantitative tomographic methods to estimate myocardial function is the inability to obtain adequate landmarks in the heart because of poor spatial resolution.
Cardiovascular magnetic resonance (CMR) tissue tagging, which is currently considered the reference method, is validated and accurate, but it is slow, has poor resolution in the slice selection direction, and requires extended breath holding, and its image analysis is time consuming because of the manual segmentation required to detect the myocardial borders. In addition, CMR imaging is still considered a contraindication in the rapidly growing population of patients with implanted pacemakers or implantable cardioverter-defibrillators.
Recent dramatic advances in cardiac CT imaging techniques allow for volumetric functional imaging of the entire heart with a few gantry rotations. The high temporal resolution acquisitions of the entire cardiac volume with wide-range detector CT allows a contrast bolus to be imaged over a short window in the heart cycle with very high spatial resolution, making visible fine anatomic structures, such as trabeculae, on the endocardial surface.
It would therefore be advantageous to provide a method for tracking the left ventricular (LV) wall motion and assessing local cardiac function in high-resolution volumetric cardiac CT images using fast, nonrigid, surface registration algorithms that match geometric features of the surface over time.